Implications of Intracoronary Ultrasound Imaging for Clinical Practice Figure 5. Angiographic views during a PCI in a chronically occluded LAD. Right anterior oblique caudal view showing the blocked LAD. FUTURE TRENDS Over the last years a number of (semi-) automated methodologies and softwares have been developed which allowed fast and reliable ICUS processing (Sonka et al. 1995, Koning et al. 2002). These systems operate in a user-friendly environment and provide accurate measurements regarding luminal, outer vessel wall and stent dimensions and thus have contributed to the broad use of ICUS in research and in the study of the atherosclerosis. Further processing of ICUS signal using radiofre- quency integrated backscatter analysis provided expedite and reliable quantification of the type of the plaque and identification of vulnerable plaques. Although there are no data to support the implementation of these technologies in clinical practice it is possible in future clinical data from on-going studies to support their use in treatment planning. Bourantas et al. recently reported the first user-friendly software which is able to provide in real time 3-D coronary artery reconstruction by fusing ICUS and angiographic data (Bourantas et al. 2008). The described system allowed reli- able and comprehensive representation of vessel morphology and plaque distribution and provides quantitative measurements which maybe useful in clinical practice and assist optimal treatment. How- ever, randomized control trials are first required to test the efficacy and the utility of this system before its broad use in therapeutic procedures. CONCLUSION In this review we have attempted to summarize the clinical indications for ICUS imaging (Table 4). ICUS may be used to assess the severity of an ambiguous lesion and plaque burden and provide information regarding the composition of the plaque. During intervention, IVUS has several potential advantages, enabling accurate choice of stent or balloon diameter and length or the need for atherectomy. Thus, although ICUS adds to the cost and duration of the procedure, it is a useful tool in selective cases as it allows correct diagnosis and may improve prognosis. 103